


Games and revenge

by Bellacia



Category: Chicago Fire
Genre: Boyfriends, Fluff, M/M, Tickling
Language: English
Status: Completed
Published: 2021-02-06
Updated: 2021-02-06
Packaged: 2021-03-18 02:40:23
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,764
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29236200
Author URL: https://archiveofourown.org/users/Bellacia/pseuds/Bellacia
Summary: Casey notices that Severide seems tense after seeing his father, so she decides to "help" him relax.Severide decides to take revenge when the time is right.
Relationships: Matthew Casey/Kelly Severide
Comments: 7
Kudos: 34





	1. Chapter 1

Severide was already in his apartment and in his bed, face down and with his arms under his pillow. He hadn't even taken off his boots before he threw himself on the bed. When he came in from his meeting with Benny, he threw his coat and bag around and went to his room, more mentally married than physically. Okay, the encounter hadn't been that exhausting, but Kelly kept repeating to his father that he would never be like him. The old man ignored that, however, and kept talking like it was nothing. It was almost as if he was in denial at his son's words. He knew he had admired him before, but Benny seemed to have stuck to that and ignored the fact that Kelly was already an adult with clear ideas. 

One shouldn't think wrong: he loved his father and respected him as a firefighter, but that would never stop Severide from noticing the flaws Benny had as a father. Although he would sometimes restrain himself and simply tell him that he should calm down his praise of himself, there had been times when the two of them had argued a lot. A lot of things hadn't been said at the time, and now that they had connected a bit, they both felt it was the ideal time to get all the bad stuff out, even if it wore them down completely. He knew his half-sister didn't think much of his father and he didn't want to be the one to give her a bad impression of the man, so he preferred to keep it to himself.

He snorted and buried his face in his pillow.

At times like this, Kelly was grateful to have Matt with him. It might sound selfish, but Severide always enjoyed the nights when they didn't go to Molly's and instead stayed in to watch a movie or just talk about anything and everything.

He heard the front door open and knew Matt had finally arrived. 

-Kelly? I'm home.

Under other circumstances he would have gotten up to greet him, but he was already comfortable, so he decided to wait for the now Captain to go to the room. He heard him put his bag down and approach his room.

-Hello...

Casey smiled as he gently shook his head and walked over to sit next to his. Wordlessly, he slipped a hand under his partner's shirt to caress the area. Kelly felt like he could melt under the touch, his muscles relaxed and he breathed easier.

-Hard day?" the blond asked.

-I should be asking you that, you know.

Matt smiled softly and said:

-More or less. Now it turns out that being Captain I have more paperwork than before.

-That's what you get with promotions. Suck it up.

-So now it's my fault?

-You said it yourself, baby.

Matt leaned over and kissed the back of Severide's neck a couple of times, holding back a laugh as he noticed the slight movement of his shoulders.

-What about you and your father? 

Kelly sighed heavily before answering. He didn't really like to bring up the subject.

-Benny doesn't understand that I'll never be like him. Seriously, I don't know what he really expects of me.

-Your father loves you. In a weird way, but he does. He only wants what's best for you.

-I'm an adult..." was all the older man said.

Casey felt his muscles tighten again. He understood that the "Benny Severide" thing was never not complicated. He continued to massage his back, trying to get him to relax. He could almost imagine his partner's expression now just thinking about his father. He wanted to do something to take his mind off it and all at once, a mischievous idea came to his mind. He knew he was taking quite a risk, but truth be told, ever since he had discovered that little weakness of Kelly's, he had been waiting for just the right moment so he could see his reaction.

He pursed his lips a little to stifle a chuckle and ran his hand down Kelly's right side, applying a little pressure. The older man tensed a little, but he must have thought it was unintentional, because within a second he relaxed again. The second time, he ran his hand down the center of her back again, this time applying more pressure. The reaction was instantaneous. Kelly arched his back slightly and gasped softly.

Realizing what he was doing, Kelly told himself he could push Matt away in one move, considering he was stronger than him, but trying to look tough as always, he tucked both arms under his pillow and buried his face in it.

"That's very adult of you," Casey teased, giving him a poke in the ribs, making him jump a little.

"Matt..." he said in a warning tone.

"Shh, shh, shh. Let's see if you can really resist," exclaimed the blond, straddling his hips. Kelly muttered something that Matt could decipher as "I hate you."

Casey began to run his hands down Severide's sides, intent on tickling him. The Lieutenant shivered at the contact and squeezed tightly the only thing that was currently his protection. Matt chuckled and ran his fingernails from the Major's shoulder blades to his lower back without losing sight of the movements of his shoulders.

Kelly squealed softly as the tingling sensation coursed through his body. He hadn't been tickled in years.

As soon as he felt Matt press lightly on both sides of his waist, Kelly had trouble suppressing the urge to laugh. He felt his body go into mild shocks every time Casey touched his waist and although he had a strong will, he was finding it hard to resist. It seemed the harder he tried, the worse the sensation became.

When he felt Matt's warm lips kiss his back, from the center of his spine, his ribs and even his sides, Kelly braced his hands on the mattress to pull Matt down, but a second later he refused to give in and returned to his previous position.

"You're playing with fire," he warned.

"You are stubborn," Matt whispered in his ear, making him shiver. A second later, he blew gently on the area, drawing a squeal from him and causing him to try to pin his ear to his shoulder.

"Stop!" he shouted with a chuckle, now raising his head.

It was only when he felt Casey's fingers lower and linger between the mattress and his stomach that Kelly finally let go of his pillow and grabbed his partner's wrists, though without turning around.

"Matt, leave me!

"But I hardly ever see you laugh like that. It's so cute," the blond exclaimed like a little boy.

He had been teasing his belly for quite a while and the teasing only made things worse for the poor Lieutenant, who was already feeling his face turning red. Although he wasn't overly delicate, that didn't stop him from feeling the flushes every time Matt touched him. His father, when he was in the house, was usually feeling animated enough to play with his son and on occasion, they would end up with Benny tapping his son on the ribs every time he was winning. He didn't hate it, really. But as an adult, he had an image to uphold and Matt could end it if he thought to talk about it at work.

God, when he got his hands on it....

But his own thought was interrupted when he felt Casey's hands caress his ribs. He exhaled shakily and rested his chin on the bed.

"Matt... Please-he gasped still between soft chuckles.

"Please what, baby?

"Don't make me say it...

"It can't be that hard," Casey teased, squeezing his ribs a little.

"It is for me!," he cried.

"Well... in that case..."

"No, no, no! Matt, please, not that!

Matt began to press and move his fingers mercilessly over Kelly's ribs and no longer able to stand it, the older man let out a wave of childish laughter that could easily be heard throughout the room. He couldn't even find the strength to turn around and remove the younger boy. Instead, he stood there helplessly as Matt continued to play with him.

As soon as he felt Casey's nails run across his lower back again, he wasn't able to resist and covered that area with his large hands.

"That's not going to stop me," the blond warned, as he sent his hands almost flying under Kelly's arms, who could barely glue them to his sides only to end up with Matt's fingers digging in. His almost desperate laughter echoed louder than before along with pleas for him to stop.

Even in the midst of his attack, Matt smiled warmly. He rarely saw Severide laugh so freely. It always caused him tenderness, his smile. Not to mention his laughter, which contrasted nicely with his gravelly voice. As the Lieutenant had told him, he knew he was taking a risk, but at that moment, he didn't care if he could see Kelly happy.

After a few minutes, Casey noticed the thin layer of sweat covering his partner's face as well as the sheen of tears in her eyes. He finally took pity on him and got off his back after kissing the back of his neck one last time. He lay down next to him still smiling, amused.

"I didn't say it," Kelly panted, gasping and turning his head to look at him.

"You got lucky," Matt exclaimed, draping an arm over Severide's back.

"I'll get my revenge, Matt Casey," the older man said as he closed his eyes. Because of this, he did not see the other's somewhat alarmed look.

What awaits me..., he thought resignedly.


	2. Chapter 2

Ever since he'd had that little game with Severide, Matt hadn't been able to stop feeling a little haunted by the idea that Kelly could get back at him at any moment. That could start from when they woke up in the morning, continue at the station and even when they went to Molly's. He couldn't deny that he was quite worried thinking that the Lieutenant could jump on him at any time to do so. Although several weeks had passed and the major showed no signs of wanting to attack him even when they were alone, Matt couldn't help but get strange ideas every now and then.

Most of his coworkers noticed how tense he seemed to be, but when asked what was wrong, he would say it was just work. Since it happened to everyone to a greater or lesser extent, they believed him and left him alone. However, that didn't stop Casey from still looking over his shoulder when Kelly walked by him. The times he came close, even the Lieutenant found himself surprised when he would tap him on the shoulder to get his attention and Matt would startle or even when he would walk by him and stop for a moment to kiss his cheek.

It was silly his fear, he knew. Kelly could be laid back and have somewhat childish attitudes most of the time, but doing "that" at work was not something that could happen. Casey was grateful for that. Because of that thought, he came to convince himself that his partner had already forgotten what happened and allowed himself to relax around it.

And that was his mistake.

One night, the two of them had decided to stay at Severide's apartment instead of going to Molly's. They bought a few beers and some Chinese food to watch a movie and that was their best plan for that night. When they finished drinking, Kelly swung his legs up onto the couch and draped them over Matt's and the blond put his hands on his knees. Neither of them were really paying attention to the TV, which was more than proven when, five minutes later, Kelly lowered his legs and reached over to start kissing Casey's cheek and neck.

"Really?" he asked with mock exasperation, as he cocked his head to the side a bit.

"What, I can't kiss my partner?" said Kelly, close to his ear.

"At the rate the movie's going, I'd even have sex right here," he blatantly blurted out. Apparently, the alcohol was having an effect.

Kelly rested his forehead on Matt's shoulder as he stifled a laugh. It was rare for Matt to talk so casually about it, and when he did, it always made Severide laugh at how minimally awkward it seemed; of course, later in bed it was another matter. 

That didn't mean he would deprive himself of grabbing his legs saying "whatever sir wants" before pulling his limbs and laying him down on the couch.

"What? Kelly, wait!" he exclaimed loudly before the older man straddled him.

"I'm not waiting anymore," Severide said seductively before capturing Matt's lips in a fleeting kiss. His strength left him and he simply let himself go. Kelly broke away for a moment to remove his coat for greater mobility. Leaning in again, Matt placed his hands on the back of the older man's neck to deepen the kiss. Casey grabbed his partner's shirt to try to pull it off, but he held his wrists and lifted him slightly off the couch.

Before he could realize it, Kelly had left his wrists under his own back and pressed both knees to his sides, preventing him from moving.

"Kelly?"

"Yes?"

"What are you doing?" he asked slightly nervously.

"Nothing... yet."

Casey looked down at his pinned arms and then looked up at his partner with some distrust.

"I'm sorry, Captain, but... I think we have a debt to settle."

Understanding this, the younger subtly tried to subtly free his arms, but had no chance at all. He dropped his head with an almost inaudible groan. One thing that characterized him was how delicate he was, in several ways. He decided to try something else. He looked at Severide in that pleading way that always softened the older man and almost succeeded. Kelly's mischievous look changed almost suddenly to one of clear doubt; he hated it when the blond used those eyes against him. Nevertheless, he shook his head and slipped both hands under Matt's shirt. Casey shuddered.

"Kelly, come on. You don't have to."

"Oh, but I want to".

Before he could beg again, Kelly had already begun to run his fingernails down Casey's well-crafted abdomen, eliciting snorts and gasps from him as he tried not to laugh. Like Kelly, he hadn't had that done to him in years either. Gabby occasionally teased him by touching his waist or ribs, but she'd never pinned him down to tickle him. Severide could take the word "give back" too literally when it came to his pride.

Matt squealed again, and his laughter turned to gleeful laughter as his fingers tickled him all the way to his ribs. He tried to arch his back to free his arms, but his attempt was rendered futile as Severide pressed his knees against his sides to prevent it. Kelly's hands went down to his waist, causing him to almost spasm. He was particularly sensitive in that area, something Sev knew from all the times he had touched him there and he jumped in surprise. He banged his head lightly against the couch, begging the older man to stop it at once, which made Severide smile. Since Kelly's hands were between his waist and his own knees, the sensation was considerably worse.

After torturing him for a minute that felt like forever to Matt, Kelly released his arms only to hold them above his head.

"Kelly, this isn't fair!," Matt shouted before bursting into desperate laughter even though Kelly hadn't touched him yet.

Raising his eyebrows a couple of times, the Lieutenant reached up to nuzzle Matt's neck with his lips, causing his laughter to mingle with soft sighs. Hearing Casey's voice seem to fade, Kelly leaned close to his ear and blew softly. His warm breath elicited a half shrill cry from Matt, who tried to press his ear to his shoulder, which he failed to do because of his partner's own head. When he felt Severide grab the top of his ear with his teeth, Casey only managed to yell, "Not that!" before laughing and screaming at the same time. His ears were horribly sensitive. Even the brush of his hair could strain him. And when they made love, Kelly didn't deprive himself of biting his lobe or even licking his entire ear. That could excite him at the same time as it caused him an almost unbearable tickle. 

Anyway, Severide had mercy and let him breathe after a moment. He didn't pull away from the area, which made Matt's breaths a little ragged, as he knew Kelly could do it again at any moment.

"Don't think I'm done, baby," the older man whispered in his ear, making him shiver.

"Kelly, come on! What else can you do to me?"

"Well..., I haven't tried to do the same thing you did to my back. I want to see how you react. Do you think so?"

"No, not really!," Matt exclaimed in panic as he realized what Severide was planning to do.

Heedless of his words, Kelly held Matt's wrists tighter and then moved down until his lips were close to the younger man's abdomen. The Lieutenant was clearly amused with the situation, as every time he just grazed Matt's skin, Matt was letting out little squeals of shock in between his giggles, causing Kelly to laugh along with him, unable to keep up with his work.

"Matt, don't distract me anymore," he scolded him.

"Sev, please don't do this," he pleaded once more.

Without answering him, Kelly began to place little kisses all over Casey's abdomen and even went so far as to nibble on the side of his waist and his left rib. All of this caused the Captain to near hysteria. His legs were shaking and he could no longer find the strength to free his arms, so he could only lie there, with no chance to protect himself.

After several minutes had passed, Kelly noticed the thin layer of sweat covering Matt's forehead, his red face and the fact that his laughter had gone silent. A pang of worry ran through him and, after kissing his belly one last time, he released him and switched positions so that they were both lying on the couch, Matt's head on his chest as he stroked his hair tenderly.

"God... that was horrible," Matt gasped, letting out a few last chuckles.

"Maybe I overdid it," the older man admitted sardonically.

"Maybe?" reproached Matt, showing him the finger marks on his wrists.

Faking an annoyed "hmm," Severide ran his hand down Matt's back as a warning.

"Kelly!" he shouted, sticking to him only by reflex.

Severide chuckled through his teeth and kissed his temple, causing Matt's face to turn redder and bury his face deeper into his chest. The older man continued to stroke his hair as his lips brushed the blond's forehead. Maybe he had indeed gone a little overboard with his little revenge. He glanced at Matt and noticed that his lips were still forming a small smile. He decided then to try something that he was sure, would please his partner.

He gently pushed Matt so that he was on his back and pulled his shirt up a little to expose his abdomen. The blond still felt tired enough to try to push the other away, so he could only speak to him.

"Kelly... please," he begged between small, nervous giggles. "Anything else you want to charge?"

"Charge? No," he replied, smiling. "I think this is better."

Matt dropped both hands to his chest and threw his head back, not really knowing what to expect from Kelly. The Lieutenant moved down until his lips were on Matt's belly and without another word, he returned to distributing soft kisses all over the area. He caressed his with his lips and even went so far as to give his small bites. Since he was being gentler this time, Casey didn't fall into hysterics, though that didn't stop some giggles from escaping his mouth when he felt Kelly's warm lips pass over his left hip bone and up to his ribs. When he repeated the same with the other side, Matt gasped softly and covered his face with both hands, trying to stifle the sounds. But the trembling of his body made it obvious, something that made the older man smile mockingly. He uncovered his face and his giggles were mixed with soft sighs. The sensation was not unpleasant. Only when he felt his tongue along the line of her abs did Casey bring his hands to Severide's shoulders.

"No..." he gasped, still giggling.

Kelly quickly slipped her arms around Matt's waist to keep him from moving and pushing him away so he could get on with his task. Seeing that he couldn't push him away, Casey covered his face again in an attempt to stifle his sounds. It was worse and more complicated when he felt Kelly's fingertips caress his sides, something that made him shiver more than before. Severide heard distinct snorts behind his hands and found that, to him, they were the most adorable sounds in the world. Matt was clearly more serious than he was, so it was more usual at the station to see him with a frown on his face and his lips in a straight line. Seeing him smiling so broadly turned out to be the most heartwarming thing Severide could have ever seen.

Kelly let go of Matt's body and moved forward to remove his hands from her face and hold them against her own chest. Then she began to shower his forehead and cheeks with kisses.

"Kelly," protested weakly, his face flushed.

"All right, all right, I'll stop now," Severide joked, leaning down beside him to hug him protectively again.

"I hope I don't get another attack from you again," Matt muttered, his eyes half closed.

"I don't think I can help it," Kelly whispered affectionately, kissing his forehead. "You have such a nice smile".

Smiling tiredly, Matt leaned more against Kelly's chest, relaxing again when Kelly stroked his hair again.

In the end, they both completely forgot about the movie. Each other's company in a moment alone would be the best reason not to have gone to Molly's

**Notes for the Chapter:**

> Hello!
> 
> I hope you liked these chapters I made from scratch because I have insomnia and I love these plots ;)
> 
> I don't know English very well, so if you see any grammar mistakes, I'll be happy if you tell me.
> 
> Greetings to all of you.
> 
> The characters don't belong to me. If they did I would have made the Sevasey real.


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